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Abstract:

Disclosed is a vibration module for a portable terminal that includes a
housing, a magnetic moving part movable in a first direction within the
housing; an elastic member supported between the opposite ends of the
magnetic moving part and inner walls of the housing, and a solenoid coil
provided in the housing. The vibration module is positioned at one end of
the moving section by the magnetic force of the magnetic moving part and
an object around the magnetic moving part, allowing the vibration module
to provide a user with a feeling similar to a click feeling via the
acceleration produced at a stopping instant. In addition, when vibrating,
the vibration module generates sufficient vibration power through
acceleration at the instant of changing moving direction at the ends of
the moving section, to provide an alarm function, such as an incoming
call notification.

Claims:

1. A vibration module for a portable terminal, the vibration module
comprising: a housing; a magnetic moving part movable in a first
direction within the housing; an elastic member supported between
opposite ends of the magnetic moving part and inner walls of the housing;
and a solenoid coil provided in the housing.

2. The vibration module of claim 1, further comprising a pair of yokes
installed on the inner walls of the housing, wherein, in response to a
signal input to the solenoid coil, the magnetic moving part vibrates in
the first direction between the yokes while being supported by the
elastic member.

3. The vibration module of claim 2, wherein, in response to another
signal input to the solenoid coil, the magnetic moving part moves from a
position in which magnetic moving part contacts one of the yokes to
contact the other one of the yokes.

4. The vibration module of claim 2, wherein when the signal is not input
to the solenoid coil, the magnetic moving part remains in contact with
the one of the yokes.

5. The vibration module of claim 1, wherein the magnetic moving part
comprises: a first magnetic part positioned at one end of the magnetic
moving part with a south pole thereof arranged adjacent to the solenoid
coil and with a north pole thereof arranged away from the solenoid coil;
and a second magnetic part positioned at the other end of the magnetic
moving part with a north pole thereof arranged adjacent to the solenoid
coil, and with a south pole thereof arranged away from the solenoid coil.

6. The vibration module of claim 5, wherein each of the first and second
magnetic parts has a pair of magnetic bodies arranged along a second
direction perpendicular to the first direction.

7. The vibration module of claim 6, wherein the magnetic moving part
further comprises a magnetic path member extending between the pair of
magnetic bodies of the first magnetic part, and between the pair of
magnetic bodies of the second magnetic part.

8. The vibration module of claim 5, wherein the magnetic moving part
further comprises a weight member having seating grooves formed on one
side thereof, with the first and second magnetic parts positioned in
respective seating grooves.

9. The vibration module of claim 8, wherein the weight member is formed
from tungsten.

10. The vibration module of claim 1, wherein the solenoid coil has a core
part arranged in the first direction and a coil part wound around the
core part, and wherein a pair of solenoid coils are arranged along the
first direction.

11. The vibration module of claim 10, wherein the magnetic moving part
comprises: a first magnetic part positioned at one end of the magnetic
moving part with a north pole arranged adjacent to a first solenoid coil
of the solenoid coils and a south pole arranged away from the first
solenoid coil; and a second magnetic part positioned at an other end of
the magnetic moving part with a south pole arranged adjacent to a second
solenoid coil and a north pole arranged away from the second solenoid
coil.

12. The vibration module of claim 10, further comprising an iron piece
arranged between the solenoid coils.

13. The vibration module of claim 10, wherein the first solenoid coil and
the second solenoid coil are arranged to generate oppositely acting
electromagnetic forces when a same input signal is applied to each of the
first solenoid coil and the second solenoid coil.

14. The vibration module of claim 1, further comprising an equilibrium
member installed on a first inner wall of the housing along the first
direction, wherein an attraction force between the magnetic moving part
and the equilibrium member attenuates another attraction force between
the magnetic moving part and the solenoid coil.

15. The vibration module of claim 1, wherein the magnetic moving part
comprises a weight member surrounding the solenoid coil and a pair of
first magnetic bodies provided on the weight member.

16. The vibration module of claim 15, wherein the magnetic moving part
further comprises a first magnetizable member provided on the weight
member surrounding the solenoid coil and the weight member, and wherein
the first magnetic bodies positioned on the first magnetizable member.

17. The vibration module of claim 15, wherein the solenoid coil comprises
a core part arranged along the first direction and a coil part wound
around the core part, and wherein the core part has a second magnetic
body and second magnetizable members provided at opposite ends of the
second magnetic body, the second magnetic body and the second
magnetizable members being arranged along the first direction.

18. The vibration module of claim 17, wherein the magnetic moving part
further comprises a first magnetizable member provided on the weight
member to wrap the solenoid coil together with the weight member, and
wherein when a signal is not input to the solenoid coil, one side inner
wall of the weight member comes into contact with one end of the solenoid
coil by the attraction force between the second magnetic body and the
first magnetizable member.

19. The vibration module of claim 17, wherein the magnetic moving part
further comprises a first magnetizable member provided on the weight
member to wrap the solenoid coil together with the weight member, the
first magnetizable member having protrusions extending inwardly of inner
walls of the weight member to face opposite ends of the solenoid coil,
wherein when a signal is not input to the solenoid coil, one of the
protrusions of the first magnetizable member comes into contact with one
of the opposite ends of the solenoid coil by an attraction force between
the second magnetic body and the first magnetic member.

20. A magnetic vibration module for a portable terminal, the magnetic
vibration module comprising: a magnetic force generator; and an
electromagnetic force generator arranged parallel to the magnetic force
generator, wherein the magnetic force generator reciprocates in response
to an input signal applied to the electromagnetic force generator.

21. The magnetic vibration module of claim 20, further comprising a first
magnetic path provided for passage of magnetic force generated from the
magnetic force generator; and a second magnetic path provided for passage
of magnetic force generated from the magnetic generator, wherein the
electromagnetic force generator generates an electromagnetic force along
the first and second magnetic paths, and the magnetic force generator
alternately uses the first and second magnetic paths to linearly
reciprocate when the electromagnetic force generator generates the
electromagnetic force.

22. The magnetic vibration module of claim 21, further comprising a
limiter provided at opposite ends of a linear reciprocating section of
the magnetic force generator, respectively, wherein the magnetic force
generator hits the limiter to generate impact force while reciprocating
in the reciprocating section between the limiter.

23. The magnetic vibration module of claim 21, further comprising an
elastic member provided at each opposite end of the magnetic force
generator, wherein a resonance frequency of the magnetic vibration module
is based on mass of the magnetic force generator and an elastic constant
of the elastic member.

24. The magnetic vibration module of claim 21, wherein the first and
second magnetic paths are cores extending and arranged along a
reciprocating direction of the magnetic force generator, and the
electromagnetic force generator are coils wound around the cores.

25. The magnetic vibration module of claim 24, wherein the first and
second magnetic paths are arranged to generate oppositely acting
electromagnetic forces.

26. The magnetic vibration module of claim 20, wherein the magnetic force
generator comprises a weight member and magnetic bodies positioned on the
weight member.

27. The magnetic vibration module of claim 26, wherein the weight member
is formed from tungsten.

28. The magnetic vibration module of claim 21, further comprising an
equilibrium member, wherein the magnetic force generator is arranged
between the first and second magnetic paths and the equilibrium member,
wherein an attraction force generated between the magnetic force
generator and the first and second magnetic paths is counterbalanced by
an attraction force generated between the magnetic force generator and
the equilibrium member.

Description:

PRIORITY

[0001] This application claims priority under 35 U.S.C. §119(a) to an
application filed in the Korean Industrial Property Office on Oct. 22,
2010, and assigned Serial No. 10-2010-0103662, the contents of which are
incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates generally to a portable terminal and,
more particularly, to a vibration module for a portable terminal, which
can provide a haptic feedback function.

[0004] 2. Description of the Related Art

[0005] Haptic feedback refers to a method for expressing information based
on a user's sense of touch and skin contact, includes providing
additional meaning by a force feedback function, for example to remotely
control a robot arm. Recently, efforts have been made to utilize haptic
feedback in portable terminals, such as cellular phones, not only as a
simple vibration function for a incoming call notification, but also as a
function for providing notification that a signal value of a key selected
by the user is normally input when the user manipulates a touch screen.

[0006] In general, when there is a call request, i.e. an incoming call, or
when a text message is received, a portable terminal provides a vibration
mode as one of various methods to provide notification of same. Operation
in the vibration mode involves operating a vibration motor of the
portable terminal.

[0007] Considering the portability of portable terminals, a coin type
vibration motor or a cylinder or bar type vibration motor may be employed
as a vibration motor in a portable terminal. However, such motors merely
provide an incoming call notification function.

[0008] Recently, with the appearance of touch screen phones, which can
provide a full-browsing screen when using the Internet or the like, input
devices, such as keypads, are implemented as virtual keypads on touch
screens. Such virtual keypads sense points contacted by a user to input
signal values allocated to the points, respectively. A typical
button-type keypad can provide a click feeling to a user with dome
switches or the like, so that the user can recognize the manipulation of
a keypad via sense of touch. Therefore, a user skilled with portable
terminal keypad data entry can recognize whether figures and characters
intended to be input by key manipulation are indeed being input without
having to visually confirm that the figures and characters being entered
by manipulation appear on a display of the portable terminal. However,
when manipulating a keypad implemented on a touch screen, the user must
directly confirm the input values through a display device since a click
feeling cannot be provided like that provided by a button type keypad
with dome switches.

[0009] As a result, efforts are being made to provide a haptic feedback
function to portable terminals equipped with a touch screen type input
device to enhance convenience and allow a user to avoid having to confirm
input values by viewing a display device. Such a haptic function for a
portable terminal is implemented by operating a vibration motor when a
touch screen is manipulated.

[0010] However, conventional coin type, cylinder type and bar type
vibration motors are limited in implementing the haptic feedback function
due to lengthy response time thereof. That is, since a residual vibration
time interval of a coin type motor, a cylinder, or a bar type vibration
motor is long, a difficulty arises when recognizing via sense of touch
whether signal values of keys manipulated by the user are correctly
input, particularly when a user rapidly and continuously inputs various
keys. A time interval of a vibration motor is a complete operation cycle,
which includes a time during which operation of the motor continues due
to inertia, until the motor completely stops.

[0011] Linear motors with low power consumption and high reliability have
been proposed as vibration motors, with improved short response time.
However, such conventional linear motors have disadvantages of having a
single resonance frequency and abruptly reduced vibration power, even if
an operating frequency deviates only about 2 to 3 Hz from the resonance
frequency. Such conventional linear motors can sufficiently provide an
alarm function, such as an incoming call notification, when operated
within its resonance frequency. However, such conventional linear motors
are also limited in providing the haptic feedback function since due to
low response velocity. That is, the linear motor can provide sufficient
vibration power after about 30 ms from the time point that an input
signal is applied, and the vibration caused by inertia can be completely
terminated after about 50 ms from the instant the input signal is
interrupted.

[0012] Therefore, although the incoming call notification function can be
sufficiently conducted using existing linear motors, there is a limit in
providing the haptic feedback function for confirming accurate
manipulation of a touch screen.

SUMMARY OF THE INVENTION

[0013] Accordingly, the present invention has been made to solve the
above-mentioned problems occurring in the conventional systems, and an
aspect of the present invention provides a vibration module for a
portable terminal, improved to have short response time, to provide a
more effective click feeling and haptic feedback function even during
time of rapid, continuous key input operation via a touch screen.

[0014] Another aspect of the present invention provides a vibration module
for a portable terminal to generate various haptic patterns corresponding
to touch screen operations, such as drag, as well as providing a click
feeling similar to a button click feeling at the time of key input
through a touch screen.

[0015] Yet another aspect of the present invention provides a vibration
module for a portable terminal to provide sufficient vibration power in
terms of an alarm function, such as an incoming call notification, as
well as providing a good haptic feedback function.

[0016] In accordance with an aspect of the present invention, there is
provided a vibration module for a portable terminal, including a housing,
a magnetic moving part installed to be movable in a first direction
within the housing, elastic members supported between the opposite ends
of the magnetic moving part and inner walls of the housing, respectively,
and a solenoid coil provided in the housing.

[0017] In accordance with another aspect of the present invention, a
magnetic vibration module is provided for a portable terminal, with the
magnetic vibration module including a magnetic force generator, and an
electromagnetic force generator arranged parallel to the magnetic force
generator, wherein the magnetic force generator reciprocates in response
to an input signal applied to the electromagnetic force generator.

[0018] The vibration modules as described above are preferably positioned
at either end of a moving section due to the magnetic force between the
magnetic moving part and an object surrounding the magnetic moving part.
Therefore, in response to an input signal applied to solenoid coil(s),
the vibration module moves from a position at one of the opposite ends of
the moving section to another position at another end of the moving
section. As a result, the vibration module provides a user with a feeling
similar to a click feeling, via an acceleration that is produced at an
instant of stopping of the vibration module. In addition, when vibrating,
the vibration module generates sufficient vibration power by acceleration
at an instant of changing a moving direction at the ends of the moving
section, thereby providing an alarm function, such as an incoming call
notification. Further, if the amplitude of the magnetic moving part is
limited by use of yokes or the like, the magnetic moving part can hit the
yokes to generate impacts at the instant of arrival at the ends of the
moving section, to generate vibration for implementing a click feeling or
an haptic feedback function in other various patterns.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and other aspects, features and advantages of the present
invention will be more apparent from the following detailed description
taken in conjunction with the accompanying drawings, in which:

[0029]FIG. 9 is a graph showing measured vibration acceleration at a
resonance frequency of the vibration module of FIG. 2; and

[0030] FIG. 10 is a top plan view showing a vibration module for a
portable terminal in accordance with another embodiment of the present
invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE PRESENT INVENTION

[0031] Hereinafter, embodiments of the present invention will be described
with reference to the accompanying drawings. In the following
description, the same elements will be designated by the same reference
numerals although they are shown in different drawings. Further, in the
following description of the present invention, a detailed description of
known functions and configurations incorporated herein will be omitted
when it may make the subject matter of the present invention rather
unclear.

[0032] FIGS. 1A to 1C schematically show the operating principle of a
conventional linear motor, and FIGS. 1D to 1F schematically show the
operating principle of a vibration module for a portable terminal in
accordance with the present invention.

[0033] As shown in FIG. 1A, when the conventional linear motor operates,
the vibration gradually strengthens, thereby limiting a rapid response of
the linear motor. In addition, it is difficult for the linear motor to
produce a haptic pattern corresponding to a rapid and continuous key
input due to vibration caused by inertia, even after interruption of an
input signal.

[0034] In addition, in such conventional linear motor, the vibrator tends
to move toward a central position away from opposite ends of a linear
reciprocating section, i.e. toward a neutral position shown in FIG. 1B,
at which position the conventional vibrator remains in a stable stopped
state. When vibrated, the conventional vibrator has a highest velocity at
the neutral position, and the velocity is gradually reduced as the
vibrator approaches either opposite end of the linear reciprocating
section, as shown in FIG. 1C, whereby the conventional linear motor
cannot produce a sufficiently high vibration power. Therefore, it is
difficult to implement an alarm function, e.g. an incoming call
notification, with such conventional linear motor.

[0035] In contrast, the vibration module of the present invention provides
a vibrator having an unstable state at the neutral position, as shown in
FIG. 1E, thereby tending to move toward one opposite end of the
reciprocating section. Therefore, as shown in FIG. 1F, the vibrator moves
to either of the opposite ends of the reciprocating section while being
gradually accelerated, thereby producing an acceleration at an instant of
changing a moving direction of the vibrator at the opposite ends of the
reciprocating section that is sufficient to provide an alarm function,
such as an incoming call notification. Moreover, since the vibrator is
installed within a confined space, the vibrator may hit the walls of the
space at the opposite ends of the reciprocating section, thereby
producing higher impact force.

[0036] The vibration module is implemented with a magnetic force generator
and an electromagnetic force generator. That is, the electromagnetic
force is generated in response to a signal input to the electromagnetic
force generator, and the magnetic force of the magnetic force generator
interact to linearly reciprocate the electromagnetic force generator.

[0037] If the magnetic force generator is formed with a fixed magnetic
path, the vibration module can effectively use the magnetic force of the
magnetic force generator. The magnetic path is provided by first and
second magnetic paths, and constant magnetic forces are produced in the
first and second magnetic paths according to input signals applied to the
electromagnetic force generator. At this time, the electromagnetic forces
produced in respective first and second magnetic paths preferably act
opposite to each other.

[0038] At the neutral position, the magnetic force generator forms a
magnetic path which passes both of the first and second magnetic paths.
However, if an input signal is input to the electromagnetic force
generator, the first and second magnetic paths produce electromagnetic
forces acting opposite to each other, which causes the magnetic force
generator to move toward either of the first and second magnetic paths.

[0039] At this time, it is possible to switch the directions of the
electromagnetic forces produced by the first and second magnetic paths by
controlling the input signals applied to the electromagnetic force
generator, which consequently allows the magnetic force generator to
alternately use the first and second magnetic paths. As a result, the
magnetic force generator can linearly reciprocate. This can be
accomplished by arranging the first and second magnetic paths along the
magnetic force generator moving direction.

[0040] The first and second magnetic paths can be implemented using a core
extending along the magnetic force generator moving direction, in which
case the electromagnetic force generator can be implemented by winding a
coil around the core.

[0041] At this time, since the attraction force between the first and
second magnetic paths and the magnetic force generator may be an obstacle
to the reciprocation of the magnetic force generator, it is desired to
provide a separate equilibrium member and to arrange the magnetic force
generator between the first and second magnetic paths and the equilibrium
member. As such, the attraction force between the equilibrium member and
the magnetic force generator will counterbalance the attraction force
between the first and second magnetic paths and the magnetic force
generator.

[0042] If the limiters are arranged at the opposite ends of the linear
reciprocating section of the magnetic force generator, respectively, the
magnetic force generator hits the limits while reciprocating between the
limits, thereby generating impact force. The impact force produced
thereby can be usefully employed for implementing an alarm function, such
as an incoming call notification, in a portable terminal.

[0043] In addition, if elastic members are provided at the opposite ends
of the magnetic force generator, it is possible to set a resonance
frequency by using the elastic constant of the elastic members. The
resonance frequency may be set in accordance with the mass of the
magnetic force generator. If the magnetic force generator reciprocates at
the resonance frequency, it is possible to additionally strengthen the
vibration power or the impact force produced at the opposite ends of the
reciprocating section.

[0044] FIGS. 2 through 10 show specific embodiments of the present
invention.

[0045] As shown in FIGS. 3 and 10, within a housing 101 or 201, the
vibration module 100 or 200 for a portable terminal includes a solenoid
coil 102 or 202 arranged in a stator form, the solenoid coil serving as
an electromagnetic force generator and forming a magnetic path; and a
magnetic moving part 103 or 203 arranged in a vibrator form as magnetic
force generator, the magnetic moving part 103 or 203 being supported by
elastic members 104 within the housing 101 or 201. As a result, the
magnetic moving part 103 or 203 is vibrated in the housing 101 or 201 in
response to a signal input to the solenoid coil 102 or 202 while being
supported by the elastic members 104. Although the term `vibration`
generally means that an object is shaken and moved, as used herein
`vibration` indicates regular reciprocation of the vibrator in a
predetermined section or moving of the vibrator from one of the opposite
ends of the section to the other.

[0046] The solenoid coil 102 or 202 is anchored in the housing 101 or 201,
and the magnetic moving part 103 or 203 is installed to be movable in the
first (X) direction in the housing 101 or 201. In the first (X)
direction, the elastic members 104 are interposed between the internal
walls of the housing 101 or 201 and the opposite ends of the magnetic
moving part 103 or 203, respectively. That is, the magnetic moving part
103 or 203 is installed to reciprocate in the first (X) direction while
being supported by the elastic members 104. If an input signal is applied
to the solenoid coil 102 or 202, the magnetic moving part 103 or 203
vibrates within the housing 101 or 201 due to an interaction between a
magnetic force of the magnetic moving part and magnetic forces produced
by the solenoid coil 102 or 202.

[0047] At this time, as shown in FIG. 2, a pair of solenoid coils 102 may
be arranged along the first (X) direction, and if the same input signals
are applied to each coil of the pair of solenoid coils, the
electromagnetic forces produced by the solenoid coils 102 act opposite to
each other.

[0048] As shown in FIG. 4A, when a signal is not applied to the solenoid
coils 102, the magnetic moving part 103 forms a common magnetic path with
the solenoid coils 102 at the central point (hereinafter referred to as a
"neutral point") of the moving section. However, if the same input
signals are applied to the solenoid coils 102, the magnetic moving part
103 is moved toward one of the solenoid coils 102 which provides
attraction force, thereby being positioned as shown in either FIG. 4B or
FIG. 4C.

[0049] If yokes 125 are provided adjacent to the opposite ends of the
magnetic moving part 103 in the housing 101, as shown in FIG. 2, the
magnetic moving part 103 can be moved toward one of the yokes 125 by the
magnetic force between the magnetic bodies in the magnetic moving part
103 and the yokes, even if small external force is applied or shaking is
caused at the neutral point. The embodiment shown in FIG. 2 illustrates
that the yokes 125 are arranged on the solenoid coils 102, respectively,
which will be described in more detail below. If the magnetic moving part
203 is formed to wrap the solenoid coil 202, it may be possible to
incorporate a magnetic body 221a within the solenoid coil 202 itself and
to add a configuration to perform the role of the yokes to the magnetic
moving part 203, as described below and shown in FIG. 10.

[0050] Consequently, in the vibration module 100 or 200 for a portable
terminal, the magnetic moving part 103 or 203, which is a vibrator, does
not remain in a stable state at the neutral point, and tends to move to
one side of the moving section even with minute shaking. Therefore, in a
state in which the vibration module 100 or 200 is mounted in a real
product, the magnetic moving part 103 or 203 is positioned at one side of
the moving section rather than at the neutral point, and vibrates or
moves to the other side of the moving section, in response to a signal
applied to the solenoid coil 102 or 202, more specifically, depending on
the frequency of an input signal.

[0051] As shown in FIGS. 2 and 3, the housing 101 has a receiving space
formed in the inside thereof, and is opened at one side. The opened side
of the housing 101 is closed by a separate cover member 101a. Among the
inner walls of the housing, seating faces 113 are formed on a pair of
opposite inner walls. Yokes 125 are attached and anchored on respective
seating faces 113, with the yokes further described below. In addition, a
plurality of slits 117a and 117b are formed in the housing 101 for
installation of the elastic members 104, or paths for wiring a flexible
printed circuit board 119 (FIG. 2) or the like.

[0052] A solenoid coil 102 includes a core part 121 arranged to extend
along the first (X) direction, and a coil part 123 wound around the core
part 121, wherein a pair of such solenoid coils 102 are arranged within
the housing along the first (X) direction. When no signal is applied to
the coil parts 123, the core part 121 forms a magnetic path with the
magnetic moving part 103. If an input signal is applied to the coil parts
123, a magnetic path is formed biased to one of the coil parts 123, with
the magnetic moving part 103. The core part 121 forming the magnetic path
with the magnetic moving part 103 can be controlled by the input signal
applied to the coil parts 123. Through this, the magnetic moving part 103
forms a magnetic path alternately with the core part 121 to produce
linear reciprocating force.

[0053] A central yoke 127 may be arranged between the solenoid coils 102,
wherein the yokes 125 are arranged between the ends of the solenoid coils
102 and the inner walls of the housing 101, respectively. The yokes 125
may be anchored to the seating faces 113, respectively.

[0054] In an embodiment of the present invention, the winding direction of
the left solenoid coil 102 is opposite to that of the right solenoid coil
102, thereby producing electromagnetic forces acting opposite to each
other when a same input signal is applied to the solenoid coils 102. As a
result, when the same input signal is applied to the solenoid coils 102,
the magnetic moving part 103 produces an attraction force with one of the
solenoid coils 102, and a repulsion force in relation to the other
solenoid coil 102.

[0055] The magnetic moving part 103 has a weight member 131 and magnetic
bodies 133a and 133b. In the present embodiment, two pairs of magnetic
bodies 133a and 133b are provided, with the magnetic bodies arranged at
the left side being referred to herein as a "first magnetic part" and the
magnetic bodies arranged on the other side being referred to herein as a
"second magnetic part" for the convenience of description. The first
magnetic part includes a pair of magnetic bodies 133a arranged adjacent
to the solenoid coils 102. The second magnetic part includes a pair of
magnetic bodies 133b arranged away from the solenoid coils 102. Although
the present embodiment exemplifies a configuration that each of the first
and second magnetic parts includes a pair of magnetic bodies, it is
possible to configure each of the first and second magnetic parts with a
single magnetic body. In such a case, if the weight member 131 is made in
a shape similar to that shown in FIGS. 2 and 3, each of the magnetic
bodies of the first and second magnetic parts will have a shape extending
in the second (Y) direction perpendicular to the first (X) direction.

[0056] The weight member 131 can provide sufficient vibration power when
the vibration module is operated by increasing the weight of the magnetic
moving part 103. Therefore, the weight member 131 is preferably
manufactured using tungsten or an alloy thereof, which has the heaviest
weight per unit mass. The weight member 131 is provided with seating
grooves 131a for arranging the magnetic bodies 133a and 133b. In
addition, protrusions 131c are formed between the seating grooves 131a
arranged in the first (X) direction, respectively, and another seating
groove 131b extends between the grooves 131a arranged in the second (Y)
direction and between the protrusions 131c. In the seating groove 131b, a
magnetic path member 135, such as an iron core, may be arranged. The
magnetic path member 135 extends in the first (X) direction. The magnetic
path member 135 stably forms a magnetic path between the magnetic bodies
133a and 133b, thereby strengthening the magnetic forces produced by the
magnetic bodies 133a and 133b.

[0057] In arranging the magnetic bodies 133a and 133b, the magnetic bodies
133a and 133b are positioned so that south poles (S-poles) thereof are
arranged adjacent to the solenoid coil 102, and north poles (N-poles)
thereof are arranged away from the solenoid coil 102. In addition, the
magnetic bodies of the second magnetic part are arranged with the N-poles
thereof are arranged adjacent to the solenoid coil 102, and the S-poles
thereof are arranged away from the solenoid coil 102. Of course, the
polarities of the magnetic bodies may be reversely arranged in relation
to the above-mentioned arrangement.

[0058] As such, the vibration module 100 also forms a magnetic path M as
shown in FIG. 4 in the interior thereof. That is, the magnetic path M
extends along the magnetic bodies 133a and 133b, and the core parts 121
of the solenoid coils 102 is formed.

[0059] In order to form the stable magnetic path M within the vibration
module 100, and to mitigate the attraction force between the magnetic
moving part 103 and the core parts 121 so that the movement of the
magnetic moving part 103 in the first (X) direction can be smoothly
conducted, an equilibrium member 149 may be provided in the vibration
module 100. On an inner wall of the housing 101 opposite to one side of
the magnetic moving part 103 in the second (Y) direction, an anchoring
groove 115 is formed, in which the equilibrium member 149 is installed.
As such, among the magnetic bodies 133a of the magnetic moving part 103,
one pair is arranged adjacent to the equilibrium member 149, and an other
pair is arranged adjacent to the core parts 121.

[0060] The equilibrium member 149 and the core parts 121 may be
manufactured from a magnetizable material, e.g. steel, to produce an
attraction force with the magnetic bodies 133a and 133b. As such, the
attraction force acting between the magnetic moving part 103 and the core
part 121 can be attenuated by the attraction force acting between the
magnetic moving part 103 and the equilibrium member 149. As a result, the
magnetic moving part 103 can move in the first (X) direction without
being biased to one side in the second (Y) direction between the solenoid
coils 102 and the equilibrium member 149 while being supported by the
elastic members 104. That is, the elastic members 104 are installed
between the magnetic moving part 103 and the inner walls of the housing
to limit the movement of the magnetic moving part 103 in the second (Y)
direction. As a result, the magnetic moving part 103 can move in the
first (X) direction without being attached to the equilibrium member 149
and the core part 121.

[0061] The elastic members 104 interconnect the magnetic moving part 103
and the housing 101, to float the magnetic moving part 103 in the housing
101. In addition, since the elastic members 104 have their own resonance
frequency, they will intensively vibrate the magnetic moving part 103
when an input signal corresponding to the resonance frequency of the
elastic members 104 is applied to the solenoid coil 102. The opposite
ends of each elastic members 104 have free ends 141 and 143 which are
bent to have shapes to be anchored to the housing 101 and the magnetic
moving part 103, respectively, and the free ends 141 and 143 are
interconnected by an elastic element 145.

[0062] Free end 141 is bound to the housing 101 through a slit 117a formed
in the housing 101, and anchored to wrap an inner wall and an outer wall
of the housing 101. The other free end 143 takes a shape bent to face a
part of the outer face of one of the opposite ends of the magnetic moving
part 103 and the equilibrium member 149, and to wrap the part of the
outer face. The elastic element 145 preferably extends in a zigzag shape,
and generally takes a "V" shape when seen from a top plan view. When the
magnetic moving part 103 is vibrated, the elastic element 145 can be
deformed to such an extent that it is positioned nearly in a single
plane. However, if the displacement of the magnetic moving part 103 is
limited, the elastic element 145 may not be positioned substantially in a
single plane. Meanwhile, each of the elastic members 104 may be formed
only by the elastic element 145 without having the free ends 141 and 143.
In such a case, the opposite ends of the elastic members 104 may be
attached to the magnetic moving part 103 and the inner walls of housing
101 through welding or the like, respectively.

[0063] As described above, in the vibration module 100, an input signal,
i.e. electric current, is applied to the solenoid coils 102 through the
flexible printed circuit board 119. As shown in FIG. 2, the flexible
printed circuit board 119 is positioned on the inside of the housing 101,
attached via slit 117b formed in the housing 101, and connected to the
solenoid coils 102.

[0064] Referring to FIG. 4 again, the yokes 125 arranged at the ends of
the solenoid coils 102 can limit the displacement of the magnetic moving
part 103. That is, the yokes 125 are arranged to interfere with the
magnetic moving part 103 at the opposite ends of the moving section of
the magnetic moving part 103. As such, if the magnetic moving part 103
moves, the yokes 125 periodically contact with the magnetic moving part
103, thereby producing impact force, and if the magnetic moving part 103
is periodically vibrated, the impact force will be regularly produced.

[0065] If an input signal is not applied to the solenoid coils 102, it is
difficult for the attraction force between the core parts 121 of the
solenoid coils 102 and the magnetic moving part 103 to keep the magnetic
moving part in the stopped state at the neutral point. Furthermore, if
the yokes 125 are provided, the attraction force between the magnetic
moving part and the yokes 125 acts more strongly, which causes the
magnetic moving part 103 to be more instable at the neutral point.
Consequently, if an input signal is not applied to the solenoid coils
102, the magnetic moving part 103 remains at one end of the moving
section, and more particularly, in contact with one of the yokes 125.

[0066] Operation of the vibration module 100 is described in further
detail with reference to FIGS. 5A to 5D. FIGS. 5a to 5c show magnetic
paths formed depending on the position of the magnetic moving part 103
and moving directions, and FIG. 5D shows a graph showing forces produced
in accordance with the position of the magnetic moving part 103.

[0067] In FIG. 5D, the horizontal axis corresponds to the position of the
magnetic moving part 103 in the first (X) direction, and the vertical
axis corresponds to the forces acting on the magnetic moving part 103.
Here, a force having a positive (+) value acts to move the magnetic
moving part 103 rightward, and a force having a negative (-) value acts
to move the magnetic moving part 103 leftward.

[0068] In addition, the curve designated by `M` in FIG. 5D indicates
forces acting on the magnetic moving part 103 when only the magnetic
moving part 103 and the yokes 124 are provided, the curve designated by
`S` indicates forces acting on the magnetic moving part 103 when the
elastic members 104 are provided together with the magnetic moving part
103 and the yokes 125, and the curves designated by `C1` and `C2`
indicate forces acting on the magnetic moving part 103 by electromagnetic
forces from the magnetic moving part 103, the yokes 125, the elastic
members 104, and the solenoid coils 102 when input signals are applied to
the solenoid coils 102.

[0069] Under the premise that the magnetic moving part 103 is arranged to
be movable only in the first (X) direction, if only the solenoid coils
102, the yokes 125 and the magnetic moving part are arranged in the
housing 101, the magnetic moving part 103 tends to move to one end of the
moving section. Although the force acting on the magnetic moving part 103
has a zero (0) value, the magnetic moving part 103 will move leftward or
rightward since it is inevitable that a small force will act on the
magnetic moving part 103. Since the attraction force between the core
parts 121 and the magnetic moving part 103 acts even if the yokes 125 are
not provided, it is impossible for the magnetic moving part 103 to remain
in the stable state at the neutral point.

[0070] If the elastic members 104 with the same elastic constants and
specifications are arranged at the opposite ends of the magnetic moving
part 103, the force acting on the magnetic moving part 103 may be
somewhat alleviated depending on the position of the magnetic moving part
103.

[0071] In addition, if an input signal is applied to the solenoid coil
102, the magnetic moving part 103 moves from left to right, or from right
to left, with FIGS. 5A to 5C showing a process in which the magnetic
moving part 103 moves from left to right. The magnetic paths formed by
the magnetic moving part 103 generally follow a clockwise pattern.
However, by changing the polarities of the magnetic bodies 133a and 133b
arranged in the magnetic moving part 103, the direction of the magnetic
paths can be changed.

[0072] By the input signals applied to the solenoid coils 102, the left
solenoid coil 102 generates electromagnetic force E2 (in FIG. 5A) in a
direction opposite to the magnetic path of the magnetic moving part 103,
and the right solenoid coil 102 generates electromagnetic force in the
direction equal to the magnetic path of the magnetic moving part 103.
Therefore, the magnetic moving part 103 moves rightward. At this time,
the `C1` curve indicates the forces for moving the magnetic moving part
103 from left to right when input signals are applied to the solenoid
coils 102, and the `C2` curve indicates the forces for moving the
magnetic moving part 103 from right to left when input signals are
applied to the solenoid coils 102.

[0073] Referring to the `C1` and `C2` shown in FIG. 5D, the forces for
substantially moving the magnetic moving part 103 in the vibration module
100 are strengthened as the magnetic moving part 103 moves toward either
opposite end of the moving section.

[0074] The term, "left" or "right" used in describing the operating
mechanism of the vibration module 100 with reference to FIG. 5 generally
indicates any one of the opposite ends of the moving section of the
magnetic moving part 103.

[0075] Meanwhile, if limiters for the moving section of the magnetic
moving part 103, for example, the yokes 125 are arranged at the opposite
ends of the moving section of the magnetic moving part 103 to limit the
moving section of the magnetic moving part 103, an impact force is
produced when the magnetic moving part 103 is vibrated, thereby providing
vibration capable of being felt by a user. At this time, as the magnetic
moving part 103 approaches either end of the moving section of the
magnetic moving part 103, the forces acting on the magnetic moving part
103 are gradually increased. Therefore, the impact force produced when
the magnetic moving part 103 hits the yokes 125 will have an intensity
sufficient to provide a haptic feedback function. In addition, if a
resonance frequency is established by arranging the elastic members 104
between the magnetic moving part 103 and the housing 101, a high
resonance vibration power is generated at the corresponding frequency to
perform the alarm function of a portable terminal, as discussed below.

[0076] A result obtained by measuring the frequency response
characteristic of the vibration module 100 configured as described above
is shown in FIG. 6, which shows a frequency response characteristic in
accordance with the change of input signals in terms of frequency when
the same input signals are applied to the solenoid coils 102 with input
voltages of ±3.3 V, respectively. As seen from FIG. 6, the vibration
module 100 produces a vibration acceleration of about 2.5 G (with G being
the constant of gravity) for the input signals less than 100 Hz, and
produces a vibration acceleration of about 3.5 G at the input signal of
100 Hz, which is the resonance frequency. Therefore, it is possible to
vibrate the magnetic moving part 100 in various patterns by applying
various frequencies less than 100 Hz as the input signals, to produce
various haptic patterns.

[0077] Meanwhile, the resonance frequency of the vibration module 100 can
be adjusted depending on the elastic constant of the elastic members 104.
For example, if the elastic members 104 with an elastic constant of 266
N/m are employed, the resonance is adjusted to approximately 80 Hz.

[0078]FIG. 7 is a graph showing a result obtained by measuring the
response time of the vibration module 100 by applying an input signal (I)
of 5V, 1 Hz to the solenoid coil. A time delay of the vibration module
100 is a time interval required to produce vibration or impact after the
input signal (I) is applied to the solenoid coil 102 and the vibration
module is operated. As shown, a time delay of the vibration module 100 of
only 6.6 ms is obtained. In comparison, for a linear motor employed in a
conventional portable terminal, approximately 30 ms is required for the
linear motor to arrive at resonance frequency after an input signal is
applied, and vibration acceleration is about 1.5 Grms (root mean square).
Furthermore, such conventional linear motor requires about 50 ms until
for vibration to stop after the input signal is interrupted.

[0079]FIG. 7 shows that the vibration module 100 has a substantially
rapid response time, and substantially does not provide residual
vibration, i.e. resonance until the vibration is completely stops after
an input signal interruption.

[0080] FIGS. 8A to 8C show results `O` obtained by measuring produced
vibration accelerations while varying the frequencies of the input signal
`I` to the vibration module 100. FIG. 9 shows results `O` obtained by
measuring the vibration accelerations of the vibration module 100 when a
resonance frequency of 100 Hz is used as the input signal `I`.

[0081] As shown in FIGS. 8A to 8C and FIG. 9, since each of the waveforms
of vibration accelerations of the vibration module 100 takes an impulse
waveform, there exists substantially no time interval until the vibration
module arrives at the resonance after an input signal is applied, or
until vibration completely stops after the input signal interruption. In
addition, since each of the vibration waveforms of the vibration module
taking an impulse waveform is substantially identical to the frequencies
of its input signal, it is possible to freely control the frequencies of
the input signal from zero (0) to the resonance frequency to generate
various haptic patterns. Furthermore, since the vibration accelerations
of the vibration module 100 are substantially higher than those of
conventional linear motors, the vibration module 100 can sufficiently
provide both a haptic feedback function and a conventional alarm
function, e.g. an incoming call notification or the like even if an input
signal with a resonance frequency is not applied. However, in order to
differentiate the time interval for operating the vibration module with a
haptic feedback function from the time interval for operating the
vibration module with an alarm function, the vibration module is
preferably set that the alarm function, such as an incoming call
notification, is executed at the resonance frequency.

[0082] In addition, if an input signal is input so that the vibration
module impacts only once, the magnetic moving part 103 will hit one of
the yokes 125 to produce impact, which can be usefully used for providing
a click feeling to a user when the user inputs figures or characters.

[0083] FIG. 10 is a top plan view showing a vibration module 200 in
accordance with another embodiment of the present invention. As compared
to the previous embodiment, the vibration module 200 in accordance with
the present embodiment has a solenoid coil 202 and magnetic moving part
203 that are different from those of the previous embodiment in terms of
construction but are similar to the previous embodiment in terms of
operation and response characteristic. Therefore, the following
description focuses on the construction of the solenoid coil 202 and the
magnetic moving part 203.

[0084] The solenoid coil 202 is anchored to the housing 201, wherein the
solenoid coil 202 is arranged at a central area of the bottom of the
receiving space. The solenoid coil 202 includes a core part, and a coil
part 223 is wound on an outer periphery of the core part, the core part
includes a magnetic body 221a and magnetizable members 221b arranged
along the first (X) direction. The magnetizable members 221b are arranged
at opposite ends of the magnetic body 221a.

[0085] The magnetic moving part 203 includes a weight member 231 arranged
to surround the solenoid coil 202, and additional magnetic bodies 233
arranged on the weight member 231. A magnetic body 233 is arranged
adjacent to each of the four corners of the weight member 231, and an
additional magnetizable member 235 is arranged on the weight member 231
to form a magnetic path M, as shown in FIG. 10. The additional
magnetizable members 235 are arranged to surround the solenoid coil 202,
together with the weight member 231.

[0086] The magnetic bodies 233 and the additional magnetizable member 235
arranged on the magnetic moving part 203 are also referred to herein as
"first magnetic bodies" and "first magnetizable members," respectively,
and the magnetic bodies 221a and the magnetizable members 221b of the
core part are also referred to as "second magnetic bodies" and "second
magnetizable members," respectively. The first magnetic bodies 233 are
positioned so that the polarities thereof are arranged along the first
(X) direction, and the second magnetic bodies 221a are positioned so that
the polarities thereof are arranged opposite to those of the first
magnetic bodies 233. As such, two magnetic paths M are formed in the
vibration module 200. Meanwhile, each of the first magnetizable members
235 has a protrusion, which extends inwardly of the corresponding inner
wall of the weight member 231 to face the opposite ends. The second
magnetizable members 221b and first magnetizable member 235 may be
selectively magnetized in accordance with the electric current applied to
the solenoid coil 202 or the magnetic bodies 221a and 233.

[0087] In the embodiment of FIG. 10, since repulsive forces act between
the first and second magnetizable members 235 and 221b, and attraction
forces act between the protrusions of the first magnetizable members 235
and the second magnetic bodies 221a, the magnetic moving part 203 is
stable at the neutral point. However, as in the previous embodiment, the
magnetic moving part 203 moves toward either of the opposite ends of the
moving section by minute shaking or the like. Therefore, the inner walls
of the magnetic moving part 203, in particular the protrusion portions of
the first magnetizable members 235 come into contact with either end of
the solenoid coil 202. A person skilled in the art will appreciate that
if sufficient attraction forces can be produced between the first
magnetizable members 235 and the second magnetic bodies 221a even if the
first magnetizable members 235 do not have protrusions extending inwardly
of the inner walls of the weight member 231, making it unnecessary to
form protrusions on the first magnetizable members 235.

[0088] In the vibration module 200 configured as described above, the
magnetic moving part 203 also moves from left to right or from right to
left, or reciprocates within a moving section of a predetermined extent,
depending on an input signal applied to the solenoid coil 202.

[0089] Consequently, a magnetic moving part is positioned at one side of
the moving section by an attraction force between the magnetic moving
part and a yoke or an attraction force between the magnetic moving part
and a solenoid coil. In response to an input signal applied to the
solenoid coil, the magnetic moving part moves from one side to the other
side, or reciprocates within the moving section, thereby producing a
predetermined impact or shock wave-type vibration. Such an impact or
shock-wave type vibration can provide various haptic patterns when a user
manipulates a portable terminal through a virtual input device
implemented on a screen of the portable terminal. In addition, the impact
or shock wave-type vibration can provide various feelings when playing a
game, as well as when performing an input action, thereby providing sense
of reality.

[0090] While the invention has been shown and described with reference to
certain embodiments thereof, it will be understood by those skilled in
the art that various changes in form and details may be made therein
without departing from the spirit and scope of the invention as defined
by the appended claims.

Patent applications by Dong-Soo Kwon, Daejeon KR

Patent applications by Eun-Hwa Lee, Suwon-Si KR

Patent applications by Tae Heon Yang, Daejeon KR

Patent applications by Young-Jun Cho, Daejeon KR

Patent applications by Young-Min Lee, Yongin-Si KR

Patent applications by Yu-Dong Bae, Suwon-Si KR

Patent applications by KOREA ADVANCED INSTITUTE OF SCIENCE AND TECHNOLOGY